Environmental Relations and Life History of the Tapeworm Bothriocephalus rarus Thomas

Abstract

The description and distribution of the tapeworm Bothriocephalus rarus has been dealt with in another paper (Thomas, 1937), in which attention is directed to the known range of this parasite which up to the present time has been reported nowhere else but in the small intestine of the vermilion-spotted newts of Sedge Pool, Douglas Lake, Cheboygan County, Michigan; Seaton's Lake, Uniontown, Pennsylvania; and an unknown locality in northern South Carolina. The tapeworm is uusual in that, to the writer's knowledge, it is the second adult pseudophyllidean tapeworm reported for amphibia and the only one thus far described for the genus Bothriocephalus that does not necessarily have a second intermediate host and that has formed bothria in the procercoid stage. These last features are a departure from the classic study by Rosen and Janici (I917-I8) on the life history of Diphyllobothrium latum and the studies of Li (I929) on Diphyllobothrium decipiens and D. erinacei. It is also different from the life cycle of Bothriocephalus cuspidatus as given by Essex (I928). It, in fact, approaches in some respects the development of Cyathocephalus truncatus Pallas as described by Wisniewski (I932a and b). The data assembled here are the culmination of experiments made and notes taken during the summers I927 to 1933 at the University of Michigan Biological Station.